Could Hood plane at high speed?

Would a battlecruiser risk planing or aquaplaning at high speed?

No; lifting such a large displacement into a plane would require a speed far beyond the ship's capability.

A capital ship of 30,000 or 40,000 tons would need much more speed to plane than its machinery could provide. A recollected calculation for Hood puts that speed at about 90 knots. The estimate is used to distinguish a fast displacement ship from a vessel lifted into a planing condition.